This invention relates to sintering and more particularly to an apparatus for separating and condensing wax from an entrainer (sweep gas) which carries the wax from a sintering furnace.
A sintering furnace takes a consolidated mass of powder and heats it in order to produce a material with a density close to a solid wrought metal. This consolidated mass of powder is held together by a binder (or lubricant) which is preferably paraffin.
Before the sintering process can begin, the particles of the consolidated mass must be separated from the wax which is holding the mass together. Batch sintering furnaces have been developed which will dewax the particles and then sinter the particles in the same chamber. In such furnaces, however, the wax must be removed from the furnace before the sintering begins.
One method of removing this wax involves the use of a "sweep" gas which entrains the wax. This sweep gas is preferably argon or nitrogen but may also be helium, hydrogen or any other residual gas typically found in a vacuum furnace. The sweep gas is introduced into the system before or during the dewaxing. Once the sweep gas has entered the furnace it must be pumped out along with the wax that has been entrained. The wax present in the sweep gas will, however, clog the pump.
To prevent clogging of the pump the wax must be removed from the sweep gas before it reaches the pump. A number of devices have been employed to accomplish this objective. Among these are falling film heat exchangers, packed bed condensers and electrostatic precipitators. These devices have been found to be only partially effective in removing the wax.
It is therefore an object of this invention to provide a wax condenser which will separate a high percentage of the wax from an entrainer gas.
Another object of this invention is to provide a wax condenser that can be used both in conjunction with a sweep gas which is introduced into a furnace in order to remove wax and in vacuum removal of wax.
It is a further object of this invention to provide a wax condenser that is of a simple construction with easily removable components in order to facilitate wax removal and maintenance.
Still another object of this invention is to provide a wax condenser which is highly reliable and efficient.